The disclosure is based on a sensor unit for a vehicle.
Generally, wheel bolts are tightened by way of example while changing tires in a workshop and after an initial period of use (typically 80 km is recommended) it is necessary for the driver to further tighten said wheel bolts. This inspection is however often omitted by the driver. Should the wheel bolts become detached whilst driving, this can lead to significant accidents and great personal injury and material damage. Hereinunder, the term “wheel bolt” is used as a fastening element of the wheel rim so that embodiments of the present disclosure can likewise be used if the fastening function is provided by means of a wheel stud and the associated wheel nut.
Sensors for detecting a wheel rotational speed and/or for detecting a tire pressure in the region of the vehicle wheels are known from the prior art. Systems that identify loosened wheel bolts in the normal driving operation of the vehicle are not known.
JP 2008157663 A discloses a device that determines the wheel rotational speed by way of an electromagnetic rotational speed sensor. In addition, a vibration sensor for detecting vibrations and a temperature sensor for detecting temperature are used in the corresponding wheel bearing. Possible abnormalities in the rotational speed sensor or in a sensor cable or in the wheel bearing are identified by way of a further device.